[Development] Is QFutureInterface internal like the other d-pointer classes?

[Lorenz Haas]

Hi,

most - if not all - d-pointer/private implementation files are
*internal* and should not be used in a "normal" project - meaning a
project that just uses Qt. These files/classes are clearly marked by

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

What about QFutureInterface? Is it safe to use it in a normal project
or can it be changed at any time like the other internal classes?

qfutureinterface.h/.cpp does not have the cited warning.
QFutureInterfaceBase is furthermore exported, QFutureInterface not.
Why? I also do not understand the comment in qfuture.h:

public: // Warning: the d pointer is not documented and is considered private.
    mutable QFutureInterface<T> d;

Okay, it is not documented, but I can read the source code, or is all
not documented Qt code considered *internal*? Hope not. The comment
also mentions "private". This is only related to the access
specification, is it? Or does private here also means *internal*?

Thanks
Lorenz